1. Technical Field
Some embodiments of the present inventive concepts relate to semiconductor memory devices, and more particularly to data storage devices including nonvolatile memory devices, and computing systems including the data storage devices.
2. Description of the Related Art
Hard disk drives (HDDs) have typically been used as data storage devices in computing systems, such as personal computers, server computers, etc. However, solid state drives (SSDs) including nonvolatile memory devices, such as flash memory devices (e.g., NAND type flash memory devices), have been developed. SSDs may exhibit higher performance and/or lower power consumption compared with HDDs. Accordingly, SSDs are beginning to replace HDDs in some applications.
In the flash memory of an SSD, an erase operation should be performed before a write operation. Further, in an SSD, write operations are performed on a page (or sector) basis, while erase operations are performed on a block basis, where a block includes a number of pages (or sectors). As data are continuously written to a flash memory, the data may become scattered over the entire flash memory. To obtain a free memory block, or a storage space to which data can be written, it is possible to perform a garbage collection operation from time to time that moves an effective page of one memory block to another memory block and erases the one memory block. However, read and write performance of the SSD may be reduced by this garbage collection operation. Further, performing the garbage collection operation may increase a write amplification that causes the number of write operations actually performed in the SSD to be greater than the number of write operations requested by a host, which can reduce the lifetime of the SSD.